[FNCW] -- A large infestation of hymenachne, one of Australia’s worst weeds, has been discovered near Kyogle. A community member reported the infestation during a recent Far North Coast Weeds (FNCW) field day, at Lismore. FNCW noxious weeds officer Rhett Patrick said that during the 1980s Hymenachne amplexicaulis was promoted as a ponded pastoral grass in NSW and a couple of Far North Coast land owners planted it. “It is now listed as a Weed of National Significance,” Mr Patrick said. “Hymenachne is a highly aggressive invader of waterways, riparian areas and drainage channels. “It spreads by vegetative fragments and seed. Each flower on a hymenachne plant is capable of producing more than 4000 seeds.

“Hymenachne forms dense mats which choke waterways and water storage areas and block drainage channels. “It readily degrades water quality and displaces native wildlife and other vegetation. “Livestock have been known to walk out on to large mats of hymenachne, fall through, get tangled up and drown. “Large mats can also be picked up during floods and tear down fences and damage other infrastructure.”Mr Patrick said hymenachne control was not easy. It was resistant to herbicide treatment and it often grew in swampy, wet areas, which were inaccessible with control equipment. Far North Coast Weeds (FNCW), in partnership with the Northern Rivers Catchment Management Authority (NRCMA), had obtained a Caring for Our Country (CFOC) grant to help combat the weed. The grant assisted FNCW to install five hymenachne warning signs at high-risk locations on the Far North Coast. The grant also helped fund several field days, held across the Richmond River catchment.

At a recent field day in Lismore a community member told FNCW where a large, previously unknown hymenachne infestation was located in the Kyogle area. FNCW also used the grant to help manage hymenachne in the catchment. It had identified 19 properties with hymenachne and the infestations covered a total area of more than 45 hectares.

FNCW routinely carried out control work on all these sites and it had eight properties close to full eradication, while the other 11 properties were being managed effectively. Mr Patrick said that FNCW thanked members of the public for their continued weed-control efforts and encouraged them to be aware of hymenachne and report any possible new sites to 6623 3833 or www.fncw.nsw.gov.au .

For more information, call FNCW weeds service manager Jim Willmott on 6623 3833, mobile 0427 335 509.